This study investigated two different expressions of the so-called curse of knowledge in primary school children: hindsight bias and outcome bias. Further, it explored the possible predictive function of false belief understanding in reducing these biases. Ninety-one children aged 7, 9, and 11 years (middle- to upper-middle class) were administered classical first- and second-order false belief tasks as well as hindsight and outcome bias tasks in a within-subjects design, while controlling for cognitive level. Both biases were found at all ages. Second-order false belief understanding seemed to reduce outcome bias but not hindsight bias. These findings indicate that the curse of knowledge is a multifaceted construct with potential relevant implications for learning in children.